Vista x64. ATI HD3850. Catalyst 8.3. Hannspree Monitor. Bad Combination?

I installed all latest Catalyst drivers and the system was stable.
I then attempted to use my Hannspree XM LM02 TFT monitor using the DVI connection. No digital output even during POST sequence. Same applied with the VGA connection. Monitor problem I thought?

However, I had been successfully using this monitor on an XP system with a Voodoo 3dfx graphics card VGA output so know the VGA ports work.

Next test was to see if the monitor worked during Windows operation. I swapped the CRT with the Hannspree and no image.
I uninstalled the Catalyst drivers and restarted on the CRT monitor so only Windows VGA drivers were being used.
Once in Windows I swapped the CRT with the Hannspree. What joy I got an image!
My next thought was that it was a driver/ resolution/refresh rate problem?
So to test this I restarted the PC with the Hannspree attached. Guess what? Nothing! No image during POST! Very strange.
Perhaps it was due to the input setting on the monitor.
So I tried this out. I booted using the CRT, swapped with the Hannspree once in windows in order to access the input setting menu on the monitor and tried the digital input and then
the VGA analogue input. On each occasion I rebooted with Hannspree attached and even tried both boots with DVI or VGA cables! No difference.
Maybe it was the cables? Got new ones, no difference!
Ok, at this point I thought the monitor was working on XP, but its the POST issue that was concerning me as it should have an image when connected. Maybe the BIOS? Got the latest BIOS and loaded optimized defaults and updated successfully. No difference
Different graphics card I thought next! I had an Nvidia Quadro 285 PCIE from work and tried that. Installed all the up to date drivers. Worked fine with CRT. Plugged in the Hannspree and booted, and oh my God, I had the boot sequence of POST. This was looking
good I thought, and then I turned my back and when I looked around again, the monitor displayed "no digital input check cables"!Arghhhh!
Must be the screen resolutions/ refresh rates causing this so I changed all that. No difference.
I uninstalled the NVidia drivers and tried again. Still no difference. Seems Vista was recognising the card and installing drivers straight away rather than assigning a standard VGA driver.

I thought about things again.
ATI Card = no output on monitor even during POST
Quadro = output during POST but not in Windows.
It's got to be the monitor or the ATI card!
I borrowed another monitor. This one was a cheap LCD monitor using a generic pnp driver.
It only has a VGA output cable, no DVI option.
Tried that with the Quadro and success all round! Yippee. It's starting to look like a monitor problem after all! I plugged in the Hannspree as well as it had two VGA inputs and it was picked up by the Nvidia Control Panel but would not display anything and fiddling with the resolutions and refresh rates rendered the working LCD inoperable! (So back to the faithful CRT to change it back)!

If the Quadro works with this generic LCD then maybe, just maybe the ATI card will work? Tried it and guess what? It did!
I did notice something though. There is a couple of seconds between the green spool bar and the vista logo when the monitor refreshes. At this point even this LCD lost an input
signal but picked it back up by the time the logo reappeared. This was the point when the Hannspree lost its signal when the Quadro was installed. Maybe the Hannspree is getting confused between Digital and Analogue connections?
In conclusion then, I have tried many different combinations and have made little progress! It's either the motherboard, the graphics Card or the monitor.
I have contacted Gigabyte to see if they can help and after more than 10 days still no response. I contacted Triplex who make the graphics card and although they responded within a day all they suggested was to update the ATI drivers, which I had advised them I had already done. They then replied with please contact your supplier for further help!
Great! I have raised an RMA for the graphics card but not 100% convinced it is the problem, which is why the RMA hasn't been approved by ebuyer yet!
I also contacted AMD ATI for assistance and received an automated "monitor troubleshooting FAQ" which did not help.
I have contacted Hannspree who said that the monitor is plug and play and should work either through VGA or DVI at POST.
So none of the companies will help, can anyone else? I'm tearing my hair out as something is wrong but I just can not find what it is!
Any help will be appreciated.
My system is a fresh new build with all recent updates/service packs and specs are as follows. Monitor spec is located here
find yourself in Hannspree - Europe

OS Name Microsoft® Windows Vista™ Ultimate
Version 6.0.6001 Service Pack 1 Build 6001
Other OS Description Not Available
System Manufacturer Gigabyte Technology Co., Ltd.
System Model P35C-DS3R
System Type x64-based PC
Processor Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4
Logical Processor(s)
BIOS Version/Date Award Software International, Inc. F10, 04/01/2008
SMBIOS Version 2.4
Locale United Kingdom
Hardware Abstraction Layer Version = "6.0.6001.18000"
Installed Physical Memory (RAM) 2.00 GB
Total Physical Memory 2.00 GB
Available Physical Memory 1.10 GB
Total Virtual Memory 4.23 GB
Available Virtual Memory 3.06 GB
Page File Space 2.29 GB
Page File C:\pagefile.sys

Display settings

Name: ATI Radeon HD 3800 Series
Adapter Type: ATI Radeon Graphics Processor (0x9505),
Description: ATI Radeon HD 3800 Series
RAM: 256.00 MB
Resolution: 1024 x 768 x 70 hertz
Bits/Pixel 32
Driver c:\windows\system32\drivers\atikmdag.sys
(26/02/2008 05:53)

Catalyst Driver info

ATI Catalyst® Version 08.3
Provider ATI Technologies Inc.
Direct3D Version 7.14.10.0567
OpenGL Version 6.14.10.7412
Catalyst® Control Center Version 2008.0225.2153.39091

Yeah I have the exact same problem on quite a few PC systems here using DVI on Vista...

The information I have found about this issue over the last year leads me to believe LCD/Flatscreen Monitors without there own drivers and using the default ones can cause problems when Vista detects a higher resolution than the ATI or NVidia driver/Flatscreen LCD supports.

I do not know how to fix this issue, sometimes DVI will work at times before totally crashing or other times only VGA works...

both ATI, NVidia and Microsoft claimed they have fixed the issue one way or another but its gone from either working with/without DVI completely to randomly crashing/working again on most systems usually caused by the resolution.

Thanks for the quick reply.

Weird thing is this monitor won't work even during POST with this ATI card. In the manual it does say when a digital output source is used the digital input on the monitor must be used. However as it worked with the Quadro card using VGA this doesn't seem correct.

Hannspree have vista 64 drivers available for this monitor which I have attempted to load but vista won't allow it (I have disabled driver signing @ F8 and administrator run cmd > bcdedit -set loadoptions DDISABLE_INTEGRITY_CHECKS)
Wonder why Hannspree felt the need to release specific drivers if its plug and play?
Even if they did work still doesn't explain the problem of no input during POST.
Do you agree that the monitor should always work during POST using the VGA connection? If so, as mine doesn't, what should I focus my attention on?

Thanks Scott

DVI should work during POST just check the monitor settings for the correct input otherwise you either have faulty hardware or its part of the DVI/Vista bug, somewhere something happens that just turns DVI off on graphics cards.